/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.optimize.evaluation;

import proguard.classfile.*;
import proguard.classfile.visitor.*;
import proguard.optimize.OptimizationInfoClassFilter;
import proguard.optimize.info.SimpleEnumMarker;

/**
 * This ClassVisitor marks all program classes that it visits as simple enums, if their methods qualify.
 *
 * @author Eric Lafortune
 */
public class SimpleEnumClassChecker implements ClassVisitor {
    // *
    private static final boolean DEBUG = false;
    /*/
    private static       boolean DEBUG = System.getProperty("enum") != null;
    //*/

    private final ClassVisitor simpleEnumMarker = new OptimizationInfoClassFilter(new SimpleEnumMarker(true));
    private final MemberVisitor virtualMemberChecker = new MemberAccessFilter(0,
        ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC, new MemberToClassVisitor(new SimpleEnumMarker(false)));

    // Implementations for ClassVisitor.

    public void visitLibraryClass(LibraryClass libraryClass) {}

    public void visitProgramClass(ProgramClass programClass) {
        // Does the class have the simple enum constructor?
        if (programClass.findMethod(ClassConstants.METHOD_NAME_INIT, ClassConstants.METHOD_TYPE_INIT_ENUM) != null) {
            if (DEBUG) {
                System.out.println("SimpleEnumClassChecker: [" + programClass.getName()
                    + "] is a candidate simple enum, without extra fields");
            }

            // Mark it.
            simpleEnumMarker.visitProgramClass(programClass);

            // However, unmark it again if it has any non-private, non-static
            // fields or methods.
            programClass.fieldsAccept(virtualMemberChecker);
            programClass.methodsAccept(virtualMemberChecker);
        }
    }
}